Pump and compressor



May 27, 1930. K. scl-lpENE 1,760,171

PUMP AND, COMPRESSOR Filed April 5, 1928 Patented May 27, 1930 UNITEE STATES KURT SCHOENE, OF HAMBURG, GERMANY PUMP AND COMPRESSOR Application filed April 5, 1928, Serial No.

This invention relates to displacement pumps and compressors, and particularly to that type in which the inlet ports are located in the cylinder walls and are controlled by the piston which opens the ports by overtraveling the same.

Such pumps and compressors are simple and inexpensive to construct, and will work at maximum suction heads, but they have heretofore suffered from the fact that their power demand is excessive, particularly when the suction head is small.

In the initial part of the suction stroke, that is, until the suction ports commence to open, work is done by the pump in creating an almost perfect vacuum. This occurs irrespective of the suction head againstwhich the pump or compressor is wor ing. When the suction ports open, the work so performed is, in large part, not usefully applied. The energy so wasted is greater when the suction head is small than when the suction head is large.

The object of the present invention is to recover as much as possible of the energy thus wasted heretofore in pumps and com pressors of this type. In this way such pumps and compressors are rendered comparable in power demand with those conventional types having suction or inlet valves which open throughout the suction stroke.

Preferred embodiments of the invention are illustrated, by way of example, in the ac- 7 companying drawing, in which,'

Fig. 1 is a vertical axial section of a cylinder and piston having my invention applied, so as to recover energy by deflection of the entering jets.

Fig. 2 is a similar view of a modified form, in which energy is recovered by reaction as well as by deflection of the entering jets.

Referring to Fig. 1 the piston is designated by 1, the cylinder by 2, a bushing by 3 and the discharge valve by 4:. The fluid flows into the cylinder-space through the ports 5. The surface of the piston 1 is curved so that the in fiowing jets of fluid are deflected approximately 180 so that they give up to the piston a great portion of their kinetic en- 267,671, and in Germany, April 14, 927.

.head, and the position and form of the suction ports are made such that the momentum flow of fluid into the cylinder will continue during the-initial portion of the discharge stroke and will terminate at or about the time the piston closes the suction ports.

The jet pressure acting on the piston during the initial portion of the discharge stroke opposes the movement of the piston and increases the work done by it, but the resulting loss is more than offset by the recovery of energy on the suction stroke, so that under the assumed maximum suction head conditions there is a net gain. When the suctionhead decreases, the jetwelocity is increased and the charge is terminated more rapidly, i. e. during the suctionstroke of the piston, and a greater portion of the kinetic energy of the inflowing jets is then utilized, said kinetic energyincreasing also with the jetvelocity. r

In this manner a dcrease of the powerdemand during the suction-stroke is .obtained in accordance with the decrease of the suction-head. At low suction-heads and in compressors the height of the ports will be selected so that the filling of the cylineer is terminated during the suction-stroke.

According to Fig. 2 the piston-bottom isof such shape that the jet of liquid acts on the piston, not only by deflection, but also by reaction. Nith this object in view a curved disk 7 is arranged above the pistcn-bctto n and connected with the same by ribs 8. Channels closed on all sides are thus formed, the cross-sections of which decrease in inward direction, and in which the energy of the jets of fluid is transmitted to the piston by reaction. r

I claim:

1. In a pump or compressor, the combination of a cylinder and a piston, the cylinder having in its wall at least one inlet port which is overtraveled and opened by the piston as the latter moves through its suction stroke, said port being arranged to direct the entering fluid obliquely inward and in the direction of such stroke of the piston, and the piston being formed with curved deflecting surfaces'in the path of such entering fluid arranged to apply usefully to-the piston the kinetic energy of the entering fluid.

2. In a pump or compressor, the combination of a cylinder and a. piston, the cylinder having .in its walls at least one inlet port which is overtraveled and opened by the piston as the latter moves through its suction stroke, said port being arranged to direct the entering fluid obliquely inward and in the direction of such stroke of the piston, and the piston being formed with a curved inwardly tapering deflecting passage in the path of such entering fluid, arranged to apply usefully to the piston, the energy of the entering fluid.

3. In a pump or compressor, the combination of a cylinder and a piston, the cylinder having in its wall at least one inlet port which is overtraveled and opened by the piston as the latter moves through its suction stroke, said port and the piston being so formed that the piston offers at least one fluid deflecting surface upon which the fluid entering through the port impinges to apply the energy of the fluid to the continued movement of the piston.

4. In a pump or compressor, the combination of a cylinder and a piston, the cylinder having in its wall a circumferential row of ports which are overtraveled and opened by the piston in its suction stroke, said ports being arranged to direct the entering fluid obliquely inward and in the direction of such stroke of the piston, and the piston being formed to deflect the entering fluid toward the center of the piston and thence in a direction reverse to the suction stroke of the piston. 7

5. In a pump or compressor, the combination of a cylinder and a piston, the cylinder having in its wall a circumferential row of ports which are overtraveled and opened 'by the piston in its suction stroke, said ports being arranged to direct the entering fluid obliquely inward and in the direction of such stroke of the piston, and the piston being 7 formed with a plurality of radially arranged I tapering passages in the path of such fluid, arranged to deflect" and throttle the flow of such fluid and discharge it near the center of the piston in a direction reverse to the suction motion of the piston.

In testimony whereof I afl'ix my signature.

KURT. SCHOENE. 

